Oven-thermometer.



No. 658.827. Patented Oct; 2, I900.

W. W. BRALEY.

' OVEN THERIIOIET-ER.

(Applibation filed June 23, 1597.

(No Model.)

WITNESSES l JEN-FUR v 3:44..

NITED STATES PATENT OFFICE.

WILLIAM W. BRALEY, OF TAUNTON, MASSACHUSETTS, ASSIGNOR OF ONE- HALF TO JOHN F. MONTGOMERY, OF SAME PLACE.

. QV N-THE o M E SPECIFICATION forming part of Letters Patent No. 658,827, dated October 2, 1900.

Application filed June 23, 1897- Taunton, in the county of Bristol and State of Massachusetts, have invented a new and useful Improvement in Oven-Thermometers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a partof this specification, in explaining its nature.

My invention consists of an oven-thermometer comprising a plate adapted to be attached to the interior of the oven-door and bearing a long lever or indicator pivoted to the plate and adapted to be operated directly by an extensible rod carried by said plate, one end of which is fixed and the other end of which operates directly upon the said lever or indicator close to its pivotal point.

The invention further relates .to means whereby said' thermometer-plate and nameplate are combined with the oven-door by the same fastening means.

It also relates to devices whereby the same thermometer-plate is adapted to be adjustable to name-plates varying in size and where-' by the samefastenings secure the thermometerplate .and iname-plate of any size to the oven-door.

It further relates to various detailsof construction and operation,which will hereinafter be explained.

In the drawings, Figure 1 is a view of the oven-door. of a stove, showing in dotted lines the operative position of myinvention. Fig. 2 is a rear view of the name-plate of a stove removed, showing the manner-of attachment of'my invention. Fig. 3 is a horizontal section on the line 3 3 of Fig. .1. Fig. 4 is a vertical section on the line 4 4 of Fig.-3,'look-ing in the direction of the arrow.

My invention comprises a rod A, of brass or other suitable metal which is extensible under the action ofheat,held securely at one end. The other end is free to move, the .movement being recorded. by means of a lever pivoted at a point near the end of the extensible rod. The-other end of the lever serves as an indicator, as will be presently'described.

I use a plate B to support the operative part Serial No. 641,861. (No model.)

of my device, which may be of any preferred shape, though it is desirable that it should be so formed as to protect the recording-lever as fully as possible from the heat of the oven. This plate is attached to the name-plate O of the stove by screws b, and. as names-plates are of various sizes I provide the slot 1), so that the plate B may be attachable to a name plate of any size.

The plate B is placed at a short distance inside of the name-plate, leaving space sufficient for the free operation of the indicatinglever. From one end of the. plate B a bracket 'Bextends toward the inner side of the nameplate, carrying the index-plate b which is visible through the hole 0 in the name-plate O. The bracket B may be made integral with the plate B or not, as desired, and it will be understood that the necessary grad uations for indicating degrees of temperature may be made on the index-plate 19 itself or on a separate card or plate, which may be attached thereto in any desired way.

The extensible rod A is held securely at one end in the block b cast integral with the plateB. The rod is adjustable lengthwise in said block by means of the screw 19 and is set in its desired position by the screw b In order. to steady the rod A, I provide a guide 19", consisting of a projection cast integral with the plate B, having a hole through which the rod A extends and in which hole said rod is endwise movable as it expands andcontracts. I preferably make use of a tip a for the rod A, made of steel or other suitable metal, held in a slotin the end of ,said rod; but-itwillbe understood that this is not a necessary part of my invention.

The lever D is pivoted or fulcrumed at d and provided with along arm 01, which serves sa an indicator, and a short arm (1 notched in close proximity to the fulcrum d to engage the tip 'a of the rod A. The long arm d is curved inwardly and passes through the slot b in the plate B, as shown in Fig. 2. The greater part of the long arm is straight, but

. near its end is formed the elbow d ,.and the extreme end d serves as a pointer in connection with the index-plate. It will be understood that nearly the entire length of the lever D is contained between the supportingplate B and the name-plate C, and thus the lever is protected from the action of heat.

In Fig. 3 is shown the manner of attachment of the oven-thermometer to an ordinary cooking-stove. In a stove of the usual kind the name-plate is attached to the ovendoor E, a hole being left in the door behind this, the lining, however, being carried across the hole. In this case the lining is brought as near as possible to the plate, so as to protect the lever D Without interfering with its action or deflecting the waves of heat from the red A. The screws 1) pass through the name-plate O, the oven-door E, the lining F, and the supporting-plate B and hold all these parts in their proper relative positions. In my invention the engagement bet ween the extensible rod and the lever is so delicate that the lever will record a very slight degree of movement thereof induced by a change in the heat of the oven. In this way I avoid the necessity of multiplying the movement of the extensible rod by the use of a complicated system of leverage. The engagement between the rod and the lever may be varied by alternating the adjustment of the rod A in the block Z2 as has already been described. It will be noticed that this construction is very simple. In order, however, to obtain sutficient movement of the indicator, it is necessary that the extensible rod bequitelong and that the indicator be long and that the rod make connection with the said lever close to the fulcrum-point, and I prefer for the purpose of accuracy to make this connection by means of a thin steel connection attached to the end of the extensible rod and brought to a thin edge at its outer end, where it enters and engages the notch in the short arm d The plate B, to which the indicating or index lever D is pivoted, is disposed vertically when the thermometer is attached in operative position to an oven-door, so that the short arm d of said lever is held in contact with f the expansion-rod A or against the steel tip a, forming part of said rod, bygravity, thus avoiding the use of springs heretofore sometimes employed in this class of devices, While the direct operation of the elbow index-lever by the expansion-rod engaging said lever near its fulcrum avoids the use of multiplyinglevers heretofore employed in many devices of this character, Thus my improved thermometer is simple in construction, so that it may be cheaply manufactured, and is accurate in operation and not liable to get out of order.

It will be understood that the adj ustingscrew b and the locking-screw b the purposes of adjusting the position of the indicator to register at zero at normal temperature.

It will be seen that the thermometer-plate, actuating-rod, indicator, and index are so combined that the actuating-rod and the pivoted end of the indicator are upon the inner are used for a side of the plate, while the index and the main portion of the indicator are upon the outer side thereof.

While it is desirable where a door is rounded to combine the name-plate and thermometerp.late together and to fasten them by the same fasteuiugs to the oven-door, yet in some cases the thermometer-plate may be attached directly to the name-plate and the name-plate fastened to the door, or the name-plate may be attached to the thermometer-plate and the thermometer-plate secured to the door.

Having thus fully described my invention,

I claim and desire to secure by Letters Pat! eut of the United States 1". The combination with an oven-door and a name-plate, as O, of an oven-thermometer comprising a supporting'plate, as B, an expansion-rod, as A, one end of which is ad justably fixed relative to said plate, and an elbow or angular index-lever having long and short arms and the short arm of which is engaged by the other or free end of said expansion-rod closely adjacent to but above the fulcrum of said lever, so that the short arm of said angular index-lever will be held in contact with said expansion-rod by the weight of the. long arm of said lever, and bolts or screws for attaching said supporting-plate to said oven-door and name-plate.

2. The combination with an oven-door and a name-plate, as (J, of an oven-thermometer comprising a supporting-plate, as B, an expansion-rod, as A, one end of which is ad- 1 justably fixed relative to said'plate, and an elbow orangularindexdever having long and short arms and the short arm of which is engaged by the other or free end of said expansion-rod closely adjacent to but above the fulf crum of said lever, and belts or screws for attaching said supporting-plate to said oven- ,doorand name-plate, the said supportingplate having a slot, as b, to adapt the thermometer to name-plates of different sizes.

3. In an oven-thermometer, the combinaition with a supporting or base plate, as B, 1 having near one end an aperture and near its j other end on its front side an indicating-scale, i of an expansion-rod at the rear side of said base-plate and oneend of which is fixed relative to said plate, and an angular or elbow index-lever having long and short arms, the short arm of said lever being'engaged by the free end of said expansion-rod closely adjacent to the fulcrum of said lever and the long arm of said lever being bent or offset to pass through said aperture to the front side of said 5 plate, so that its free end may serve as a 1 pointer or index at said indicating-scale.

4. In an oven-thermometer, the combination with a supporting or base plate, as B, E having nearone end an aperture and near its 5 other end on its front side an indicating-scale, of an expansion-rod at the rearside of said base-plate and one end of which is fixed relative to said plate, an angular or elbow indexlever having long and short arms, the short arm of said lever being engaged by the free end of said expansion-rod closely adjacent to the fulcrum of said lever and the long arm of said lever being bent or ofiset to pass through said aperture to the front side of said plate, so that its free end may serve as a pointer or index at said indicating-scale, a name-plate, as 0, having an opening through which the said indicating-scale and the pointing end of said index-lever may be observed, and means IO for connecting saidbase-plate with said nameplate.

WILLIAM W. BRALEY. In presence of- T. H. TATTERSALL, E. H. WALDRON. 

